Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/218

198 and are more transparent; I examined for comparison those of many kinds of Orchids which had been kept in spirits, and in all found them much less transparent. In C. tridentatum, the ovarium is shorter, much less deeply furrowed, narrower at the base, and internally more solid than in Monachanthus. Again, in all three species of Catasetum the ovule-bearing cords are short; and the ovules present a considerably different appearance, in being thinner, more transparent, and less pulpy than in the numerous other Orchids examined for the sake of comparison. Perhaps these bodies hardly ought to be called ovules, although they correspond closely in general appearance and position with true ovules, for I was unable in any case to make out the opening of the testa and the included nucleus; nor were the ovules ever inverted.

From these several facts, namely,—the shortness, smoothness, and narrowness of the ovarium, the shortness of the ovule-bearing cords, the state of the ovules themselves, the stigmatic surface not being viscid, the transparent condition of the utriculi,—and from neither Sir R. Schomburgk nor Dr. Crüger having ever seen C. tridentatum producing seed in its native home, or when artificially fertilised, we may confidently look at this species, as well as the other species of Catasetum, as male plants.

With respect to Monachanthus viridis, and Myanthus barbatus, the President of the Linnean Society has kindly permitted me to examine the spike bearing these two so-called genera, preserved in spirits, which was sent home by Sir E. Schomburgk. The flower of the Monachanthus (A, fig. 31) resembles pretty closely in external appearance that of Catasetum tridentatum (fig. 30). The labellum, which holds the same relative position to the other parts, is not nearly so deep,